7430782824ERN74320131118qHTS assay to identify small molecule antagonists of the estrogen receptor alpha (ER-alpha) signaling pathway: SummaryU.S. Tox21 ProgramNational Center for Advancing Translational Sciences [NCATS]NIH Chemical Genomics Center [NCGC]U.S. Environmental Protection Agency [EPA]National Institutes of Environmental Health Sciences [NIEHS]National Toxicology Program [NTP]U.S. Food and Drug Administration [FDA]Tox21 Assay Overview:Estrogen receptor (ER), a nuclear hormone receptor, plays an important role in development, metabolic homeostasis and reproduction. Two subtypes of ER, ER-alpha and ER-beta have similar expression patterns with some uniqueness in both types. Endocrine disrupting chemicals (EDCs) and their interactions with steroid hormone receptors like ER causes disruption of normal endocrine function. To identify the compounds that inhibit ER-alpha signaling, an ER-alpha-UAS-bla GripTiteTM cell line (Invitrogen, Carlsbad, CA, USA) containing a beta-lactamase reporter gene under the control of an Upstream Activator Sequence (UAS) stably integrated into HEK293 cells was used to screen the Tox21 10K compound library. The cytotoxicity of the Tox21 compound library against the ERalpha-bla cell line was tested in parallel by measuring the cell viability using CellTiter-Glo assay in the same wells.Please refer to other AIDs, 743069 and 743074, for detailed assay protocols.This summary is written for the purposes of summarizing the compound activities from the project combining the results from both the ER-alpha antagonist mode assay (AID 743069) and cell viability counter screen (AID 743074). For all inactive compounds, PUBCHEM_ACTIVITY_SCORE is 0. Active compounds have PUBCHEM_ACTIVITY_SCORE between 40 and 100. Potency and efficacy were used for determining relative score. Inconclusive compounds have PUBCHEM_ACTIVITY_SCORE between 5 and 30 determined by phenotype.Disclaimer:Although all reasonable efforts have been made to ensure the accuracy and reliability of the data, caution should be exercised when interpreting the results as artifacts are possible from nonspecific effects such as assay signal interference. The curve fitting and activity calls presented here are based on the NCATS analysis methods. Alternative analysis methods and interpretations of the data are available at EPA (http://actor.epa.gov) and NTP (http://tools.niehs.nih.gov/cebs3/ui/).743069ER-alpha antagonist mode screen743074Cell viability counter screen2099215432821Activity SummaryType of compound activity based on both the ER-alpha antagonist mode screen and the cell viability counter screens.42542Ratio ActivityType of compound activity in the ratio readout of the ER-alpha antagonist mode screen.42543Ratio Potency (uM)The concentration of sample yielding half-maximal inhibition in the ratio readout of the ER-alpha antagonist mode screen.154Ratio Efficacy (%)Percent inhibition in the ratio readout of the ER-alpha antagonist mode screen.1155530 nm ActivityType of compound activity in the 530 nm readout of the ER-alpha antagonist mode screen.42546530 nm Potency (uM)The concentration of sample yielding half-maximal inhibition in the 530 nm readout of the ER-alpha antagonist mode screen.157530 nm Efficacy (%)Percent inhibition in the 530 nm readout of the ER-alpha antagonist mode screen.1158460 nm ActivityType of compound activity in the 460 nm readout of the ER-alpha antagonist mode screen.42549460 nm Potency (uM)The concentration of sample yielding half-maximal inhibition in the 460 nm readout of the ER-alpha antagonist mode screen.1510460 nm Efficacy (%)Percent inhibition in the 460 nm readout of the ER-alpha antagonist mode screen.11511Viability ActivityType of compound activity in the cell viability counter screens.425412Viability Potency (uM)The concentration of sample yielding half-maximal inhibition in the cell viability counter screen.1513Viability Efficacy (%)Percent inhibition in the cell viability counter screen.11514Sample SourceWhere sample was obtained.42541estrogen nuclear receptor alpha [Homo sapiens]3480196271Homo sapienshumantaxon96063255